COMPUTATIONAL MODEL VALIDATION OF A NON-FIRING COMPRESSION IGNITION ENGINE AND CHEMICAL KINETIC MECHANISM SELECTION FOR DIESEL-PILOT ASSISTED METHANE COMBUSTION

In this study, a computational fluid dynamics (CFD) model of a single-cylinder compression ignition engine is developed and validated under motoring conditions. The engine used is the Ricardo Hydra engine at the Advanced Combustion and Energy Systems laboratory at Stony Brook University, which is highly instrumented to collect all data necessary for experimental validation of high-fidelity 3-D model simulation. The model is validated against experimental data for various intake pressures and temperatures. The results show that the model can predict the in-cylinder pressure trace with a peak-pressure accuracy ranging from 0.8% to 1.9% while the trapped mass accuracy ranges from 0.9% to 2.3% depending on the operating conditions. A skeletal chemical kinetic mechanism for diesel fuel is also presented. The mechanism is validated against experimental data for ignition delay, NOx formation, and PAH formation. The results show that the mechanism can accurately predict the combustion behavior of diesel fuel. The validated CFD model and chemical kinetic mechanism will be used in future studies to investigate the potential of diesel-piloted methane as a low-carbon fuel.